Shaft/alignment - possible problem.

Down2TheC · **Posted:** 02 Nov 2014 09:54

I noticed last season that the shaft was no longer centered in the stern tube. It's in contact with the lower edge as it exits the hull. I asked the yard about it and they claimed that it didn't matter because once the mast was on and tuned it would surely be fine. But 30 years with a boat, "new looks" are not welcome. So I checked under water (with 58 degree water- yikes!) and it seemed to have the same position.

My guess is that I'm in need of alignment/adjustment of the engine mounts? I've never touched them and found the top nuts of two of them to be freely spinning on one occasion. We have low hours but plenty of years on the old W50... time for new mounts or just try to adjust them to hike up the engine a tiny bit?

Thoughts, opinions, suggestions welcome. Suggestions that don't involve weeks of work and thousands of $$$ are more welcome.

puffcard · **Posted:** 02 Nov 2014 14:29

I agree with the yard it doesn't need to be centered thru the hole, just the shaft log and packing. Need to be in the water, with the mast installed and tuned. Loosen the 4 bolts at the coupling and slide the shaft back a little. Get out the feeler gages, with the shaft pulled back slide it up to the gage. Check that gage all around, check height, check displacement side to side. My bet, the engine is low in the back. Now look at the mounts, any cracks, does the rubber seem to lost it's flexibility, if good adjust. If bad replace. I did mine 11 years ago and they were in fair shape at best, rusty and stiff. The replacement isn't that hard, do the front first. Remember all you can adjust is the height and angle in the horizontal plane. If you. Going side to side, you're moving the mounts.

Down2TheC · **Posted:** 02 Nov 2014 15:40

Sounds reasonable. I'm assuming the old mounts have let the rear of the engine settle a bit. Then again, the stuffing box seems happy so the line from the stuffing box to the skeg should be a pretty fixed thing. Just freaks me out to see the shaft touching the edge like that. (By touching, I mean pressing. The shaft is polished by the rubbing.) I used to tape off the shaft for bottom painting and be able to slide tape and paper... so it's definitely changed in the past two years. (just comparing past cradle to current cradle look. no mast) Perhaps I'm paranoid.

puffcard · **Posted:** 02 Nov 2014 22:17

That does sound pretty bad. The shaft on mine, comes out right thru the middle. Frist thing to do is unbolt the coupling and see what the natural position of the shaft is. I think you're looking at mounts, things changing is a sign of a engine that has moved.

I've heard many say to disconnect the shaft when on the hard. I didn't see that much change from being on the hard with the Tartan. I installed my mounts while in the water, disconnected once on hard with the rig in, not that much chaged. Saw a huge difference with an O'Day I sailed on, that boat flexed a bunch once the rig was turned up.

Down2TheC · **Posted:** 03 Nov 2014 11:57

Sounds good, I'll surely start with that. Since she's going on the cradle today I guess I'm in no hurry.

(first weekend without a boat... withdrawals imminent.)
Mad

alpinista · **Posted:** 03 Nov 2014 12:22

We replaced Betty Lou's mounts on the advice of the yard when we replaced the shaft, coupling, cutlass bearing and added a dripless shaft seal. The OEM mounts were stiff and pancaked. We noticed much reduced engine vibration after replacing the mounts, so that's a bonus.

T37Chef · **Posted:** 03 Nov 2014 14:41

I see a new cutlass bearing your future, sorry. Confused

berwick · **Joined:** 21 Oct 2006 18:12 **Posts:** 325

Your strut may have loosened and gone out of alignment, there are shims underneath of them, at least in mine there is. I had to adjust it to line it up to the middle of the stuffing box, then I aligned the engine to that. If you only align the shaft (end of coupler actually) to the engine it still may not be going through your strut straight and will wear out your cutlass bearing. In other words all three should line up.

Richard

puffcard · **Posted:** 03 Nov 2014 23:23

The shafting system is essentially a free-floating, semi self-aligning system. The engine is mounted on rubber mounts, and the shaft is mounted in rubber bearings. Of course rubber being soft, that means that both the engine and shaft can and do move and will get in alignment. Watch how much the shaft and motor move. Think about all the force that's pushing your boat, transfers to the motor mounts. From the prop, up the shaft, to the transmission which is coupled to the engine, to those +30 year old mounts. Thats were all the forward force is transferred to the boat.

My strut didn't have shims. Most shaft alignments, the adjustment of the engine is moved relative to the position of the shaft, because the shaft’s position is assumed to be nonadjustable.

Mike · **Joined:** 09 Jul 2008 12:51 **Posts:** 251

I posted this topic in another thread. Last year I was doing some maintenance on the engine, dropped something and when I looked up I could see that the engine mount nuts had dropped out of their mounts. Luckily both bolts were still in the holes and prevented the engine from moving sideways.

It's something to check at least twice a year.

Tartan37.com

Shaft/alignment - possible problem.

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